1. Field of the Invention
The present invention relates to a flat image display apparatus including an electron-emitting device and a light-emitting member. More particularly, the present invention relates to an atmospheric pressure-resistant support structure (e.g., a spacer) to hold a distance between an electron source substrate on which an electron-emitting device is formed and a substrate on which a light-emitting member is formed.
2. Description of the Related Art
Hitherto, for image display apparatuses such as a cathode ray tube (CRT), a larger screen has been in demand but at a lesser thickness and weight than were provided previously. As an image display apparatus having a reduced thickness and weight, the inventors have previously proposed a flat image display apparatus using a surface-conduction electron-emitting device. In the image display apparatus using such an electron-emitting device, a rear plate (substrate) including the electron-emitting device and a face plate (substrate) including a light-emitting member that emits light in response to being irradiated with electrons, are arranged to face each other. A space between both the plates is sealed off at their peripheral edges by bonding a frame member to the peripheral edges, thereby forming a vacuum container. That type of image display apparatus includes an atmospheric pressure-resistant support structure, called a spacer, interposed between the substrates in order to prevent deformations and breakage of the substrates caused by a difference in air pressure between the interior and exterior of the vacuum container. The spacer is typically in the form of a rectangular thin plate and is arranged with its opposite ends contacting both the substrates such that space surfaces are extended parallel to the direction normal to the surface of each substrate.
The spacer is made of an insulator, e.g., a glass material, similarly to the rear plate and the face plate. However, if the surface of the spacer made of an insulator is charged, the trajectory of an electron beam emitted from the electron-emitting device is affected in some cases. One solution to cope with such a problem is to form, on the spacer surface, an electro-conductive coating that has a small secondary electron emission coefficient. Japanese Patent Laid-Open No. 2000-90859 (U.S. Pat. No. 6,265,822) proposes a spacer having a coating of carbon nitride.
However, the inventors have recognized the following problem with the related art. When an image display apparatus provided with the known spacer having the coating of carbon nitride is continuously operated, the trajectory of an electron beam is changed from an initial state, thus resulting in a change of the position of a light-emitting point.